A fresh analysis of documents disclosed by former U.S. intelligence contractor Edward Snowden shows that AT&T has been a much closer and eager partner for the National Security Agency’s Internet spying activities than was previously known.

AT&T has been by far the most critical telecom player in the NSA’s surveillance efforts and its willing participation in mass spying on both foreign and U.S. citizens has apparently been crucial in helping the U.S. agency take advantage of bulk record collection laws, according to a joint report in ProPublica and the New York Times.

AT&T insists it adheres to the letter of the law. “We do not provide information to any investigating authorities without a court order or other mandatory process other than if a person’s life is in danger and time is of the essence,” AT&T said Saturday, in response to the report. “For example, in a kidnapping situation we could provide help tracking down called numbers to assist law enforcement.”

By examining various documents supplied by Snowden, however, ProPublica and the New York Times were able to identify AT&T as the telecom player behind the so-called Fairview program, a key part of the NSA’s mass surveillance activities. In 2011, for example, the NSA’s budget for Fairview was $188.9 million, twice the amount spent on Stormbrew, a surveillance program involving Verizon, accoriding to the report.

That year, AT&T started to hand over 1.1 billion domestic cellphone calling records a day to the NSA in an effort to ramp up operations prior to the 10th anniversary of the Sept. 11, 2001, terrorist attacks on the U.S., according to the report. The disclosure stands in contrast to statements officials have made that for technical reasons, call-record programs consisted mostly of landline phone data, the report pointed out.

In 2012, AT&T gave technical help to the NSA to carry out a secret court order for the wiretapping of all Internet traffic at the U.N., a company customer, in New York, according to the examination of the Snowden documents.

In 2013, AT&T deployed surveillance equipment in at least 17 of its Internet hubs in the U.S., many more than Verizon, and the company’s engineers were the first to test out new surveillance technology developed by the NSA, the report said.

Technology companies named in the reports have said that their dealings with the NSA have adhered to legal guidelines, and many tech officials have openly called for curbs on U.S. surveillance, declaring that mass spying efforts harm business interests.

AT&T, however, has been especially helpful to the NSA, leaked documents show. “One document described it ‘as highly collaborative,’ while another lauded the company’s ‘extreme willingness to help,’ “ according to the report. AT&T surveillance assistance, via the Fairview program, dates back prior to the 9/11 attacks and the enactment of USA Patriot Act spying provisions, all the way to the mid-1980s after the company emerged as a long-distance powerhouse in the wake of the breakup of the Bell System.

The Foreign Intelligence Surveillance Act requires a court order to target someone in the U.S. But court orders are not required when a foreigner outside the US communicates with an American, and when foreigners are messaging other foreigners, the report notes. AT&T and other telecom companies apparently “sift” Internet data before handing it over to the NSA, according to the report, an arrangement that reportedly helps the government agency to work within legal boundaries.

But documents disclosed by Snowden stress that AT&T is an especially eager NSA partner, and that its “corporate relationships provide unique accesses to other telecoms and I.S.P.s,.”

ProPublica and the New York Times were apparently able to link Fairview to AT&T through a careful examination of documents disclosed by Snowden, matching up terminology and events with pubic records. “A Fairview fiber-optic cable, damaged in the 2011 earthquake in Japan, was repaired on the same date as a Japanese-American cable operated by AT&T. Fairview documents use technical jargon specific to AT&T,” the report said.

Over the past two years, information leaked by Snowden has led to ongoing debate in the U.S. about the scope of government spying. In June for example, the U.S. Senate passed legislation to curb the NSA’s bulk collection of domestic telephone records.

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